Is It The Right Time?

My boyfriend and I have been together for 3 and 1/2 years. I love him very much and I feel he is the one. He asked me to marry him three weeks ago and I can`t bring myself to say yes completely. We`re both 21 (yes, we are young) and I have finished my Bachelor`s degree and he has finished his A.A. Degree and is working on his Bachelor`s in Education..

This is the problem however--I got accepted to grad school to get my Master`s in Medical Science and Physician Assistant Degree abt three hours away. He wants to come with me and marry me, not becasue we don`t believe in living together before we are married but he feels he can`t spend all that time away from me.

Ultimately, my question is, should I get married before I attend the medical program? Or should I wait 3 years? (Which sounds like a LONG time?) Should I deal with the stress of a marriage AND my studies? WIll I have enough time to be a good wife AND a good student? How will this hurt me financially? So many questions!!